Focusing device for projectors



J. WmOBLOCK.

FOCUSING DEVICE FOR PROJECTORS.

APPLICATIONIFILED MAR. 22. 1918.

1,841,472. Emma ay 25, 1920.

is 4 I .5 4 67 2 C%AM-AI W1 1? a UNITED STATES PATENT OFFICE.

JAMES W. KNOBLOCK, OF NEW YORK, N. Y., ASS-IGNOR TO AMERICAN LA FRANCE- FIRE ENGINE 00., INC., ELMIRA, NEW YORK, A CORPORATION OF NEW YORK.

i FOCUSING DEVICE FOR PROJECTORS.

Original application filed June 19, 1917, Serial Specification of Letters Patent.

1918. Serial No. 223,963.

1 b all whom it may concern:

Be it known that I, JAMES W. KNOBLOCK, a citizen of the United States, residing in New York, in the county of New York and State of New York,'have invented certain new and useful Improvements in Focusing Devices for Projectors, of which the following is a full and clear specification.

This case, which is a division of my original application, Serial No. 175,626, filed June 19th, 1917, for improvements in elec-' tric hand lanterns, covers a novel device for supporting and focusing an electric light bulb with reference to thereflector of an electric lamp. The invention is illustrated and described with particular reference to an electric lantern because that is the form in which it is illustrated in the above named original application, but it will be understood that the invention is of broader application and may be used in various forms of electrically illuminatedprojectors, lamps, etc.

In order that the invention may be fully understood I will first describe the same with reference to the accompanying drawing and afterward point out the novelty more particularly in the annexed claims.

The accompanying drawing illustrates a vertical longitudinal sectional view of an electric hand lantern having the present invention applied thereto.

1 is a sheet metal casing or container of general rectangular configuration formed with a reinforced bottom 2, a removable cover 3 for the open top, a Vertically elon gated central depression or recess 4 in the back wall, and a circular inwardly flanged rim 5 projecting slightly from the front wall to form a support for the lamp reflector and the protecting lens or front glass.

20 is the ordinary concave reflector formed with an annular flan e which is presented within the inwardly anged' rim 5, to which it is ri idly secured by rivets or screws and nuts, ince the flanged rim 5 projects over the edge of the reflector 20, it will be understood that an effective spray proof joint between the two is obtained.

The reflector 20 is provided, as usual, with a central socket or opening 20 in which is mounted a flanged collar 45, carrying a set screw which engages a second collar 47, mounted concentrically within the collar 45,

and projecting rearwardly and formed at its inner end with a slightly contracted throat-48, in which is mounted a cylindrical lamp socket 50 containing the usual internal arrangement of contacts and wires. Thesocket 50 is formed with bayonet joint slots 51,.with which engage the oppositely pro jecting radial pins or screws 52, projecting from the base of the electric bulb 53.

The lamp supporting socket 50 is freely fulcrumed in the contracted throat 4:8 and has ample clearance in the forward end of supporting collar 47,. so that it can rockfreely up or down or sidewise or at any.

cient freedom of movement for the purpose.

explained. This mounting of the lamp socket also permits the adjustment of the lamp either forward or backward within the reflector to obtain a proper focus in the reflector, for making either a concentrated beam of light or a wider spread of light, as

may be'desired.

is a yokeor cup-shaped member open at the top to permit the entrance of circuit wires to the socket 50 and closely engaging and frictionally connecting with the rear end of the socket 50. This member 55 is rigidly mounted upon the inner end of a screw stem 56, threaded through a sleeve 57 providedat its outer end with a knurled head 58 and at its inner end with a collar 59, confining a spring washer 59 against the head 61 to frictionally hold sleeve 57 in position. The sleeve 57 rotates freely in a concentric sleeve 60, rigidly connected with the inner head 61, engaging the inner con- Patented May 25, 1921). No. 175,626. Divided and this application filed March 22,

The socket mem-Z cave face of the inset plate 62 (hereinafter referred to) the sleeve 60 passing through the enlarged opening 63 of plate 62 and carrying at its outer end the milled. clamping nut 64, which engages the outer convex face of plate 62 and the lock nut 65, which engages the nut-64. Nuts 64 and 65 are threaded uponthe sleeve 60.

The inset plate 62 is secured upon the inner face of the wall of depression a of the lamp casing, above referred to. This depression 4 has an opening 4 fcutthrough itsinner wall and the inset plate 62 has a shallow dished or spheroidal portion 62, which'rests in the cut out 4 directly behind thercentral axis of reflector 20. This inset plate 62 is secured to the metalfcasing by means of'set screws shown at From the described construction of adjustable bulb supporting devices it will be 3 understood that by loosening the. nuts 64 and 65 thefscrew stud 56 can be shifted up or downor sidewise or at'any angle in the lamp casing, 1 carrying with it the lamp socket 50am bulb 53, thesocket being fulcrumed in the throat ofthe collar 47. \Vhen the bulb is properly centralized in the reflector 20, the nuts 64: and 65 are tightened to retain this adjustment, Then by means of the knurled head 58 the sleeve 57 can be rotated to move the screw stem 56 and connected socket 50 inwardly or outwardly to 7 get the desired focus. 1

No attempt has been made to illustrate the electrical connections between the source of electricity and *the lamp supporting socket 50 nor the controlling switch. These may be arranged as shown in my above named original application of which this is a division, or they may be differently ar ranged depending upon the application of the invention, since these devices are outside oi": the scope of the present invention.

The adjustable mechanism for supporting the lamp bulb enables the adjustment-of the bulb while, the lamp is burning and by means' of such adjustment the desired result can be obtained for the various uses, for which'the lamp isisuitable.

Iclaimz r 7 1. In a device of the characterydescribed, thecombination of a suitable casing, a re flector secured in the front wall of said casing, a collar secured to the rear ofsaid refiector, a bulb supporting socketyadjustably mounted in said, collar, a rotatable threaded sleeve projecting through an enlarged opening in the'rear wall of said casing, and adjustable transversely therein, a threaded stem screwedinto saidsleeveand connected with said bulb supporting socket, means for adjusting saidsle'eve at an angle to the axis.

of the reflector, and means for rotating said sleevetoadjustisaid stem therein.

2. In a device of the character described, the combination of a suitable casing, a refiector secured "therein, a bulb supporting -socket adjustably' mounted upon said refiector, a portion of the rear wall of said casing formed with a spheroidal recess having an opening through it, a threaded sleeve, carrying a clamping nut, extending through i said rear wall opening and adjustable therein at any angle transversely of the axis of.

the reflector, a threaded stem suitably con nected with the bulb supporting socket and adjustably mounted in said threaded sleeve.

JAS. \V. KNOBLOCK; 

